A rotating electric machine is well known in which its rotor and stator are housed or accommodated in the interior of its frame, and these rotor and stator are arranged to be cooled by a cooling fluid such as a hydrogen gas or the like being pressurized and sealed in the interior of the frame, for example. Usually, in this kind of rotating electric machine, the cooling fluid in the interior of the frame is cooled by a cooling device(s) mounted in the frame's interior (for example, refer to Patent Document 1, Patent Document 2 and Patent Document 3).
In addition, conventionally, there exists a rotating electric machine which includes a cooling fluid duct on the periphery of a frame accommodating a rotor and a stator thereinside so as to cool the rotor and the stator by a cooling fluid sealed in the interior of the frame, for example, by a low-pressure hydrogen gas or the like, and at the same time, is arranged to cool this cooling fluid by a cooling device(s) mounted within the cooling fluid duct.
FIG. 18(a) and FIG. 18(b) are configuration diagrams illustrating a conventional rotating electric machine as disclosed in Patent Document 1; FIG. 18(a) is the configuration diagram illustrating it by a vertical or longitudinal section, and FIG. 18(b) is the configuration diagram illustrating it by a cross section. In FIG. 18(a) and FIG. 18(b), a rotor 2 which is accommodated in the interior of a frame 1 cylindrically formed is supported to be rotationally movable by means of bearings (not shown in the figures). A stator 4 which is accommodated in the interior of the frame 1 includes a stator winding(s) 5. In an inside space portion of the stator 4, the rotor 2 is inserted, and an inner circumferential face of the stator 4 opposes to an outer circumferential face of the rotor 2 by means of a predetermined gap 6 therebetween.
The stator 4 includes a plurality of stator ducts 8 that extend in radial directions of the stator 4, and the gap 6 and a frame's internal space 7 in the interior of the frame 1 are allowed to communicate with each other by way of the plurality of stator ducts 8. A pair of cooling fans 91 and 92 fixed on both end portions of the rotor 2 in an axial direction thereof is mounted to oppose to each other on both the end portions in the axial direction of the stator 4 and the rotor 2, and thus the cooling fluid is transported under pressure into the gap 6 in axial directions from both the end portions.
The cooling devices 10a and 10b mounted in the frame's internal space 7 in the interior of the frame 1 are placed on both sides in upper portions of the stator 4 along a direction in which an axis line X of the stator 4 extends. Each of the cooling devices 10a and 10b includes a first end-face portion 101 through which a cooling fluid flows into the cooling device, and a second end-face portion 102 from which the cooling fluid that has been cooled is outflowed. The first end-face portion 101 and the second end-face portion 102 are placed in parallel with each other.
The cooling devices 10a and 10b each include a plurality of cooling pipes (not shown in the figures) which extend along the respective first end-face portion 101 and second end-face portion 102, connecting therebetween. Those cooling pipes are separated for outward paths and inward paths by means of a pair of headers 103 and 104, and connected in parallel with each other. A cooling medium such as a cooling water or the like flowed from an inflow pipe 105 into the header 103 arrives at the header 104 through a plurality of outward cooling pipes and returns to the header 103 through inward cooling pipes, and outflows from an outflow pipe 106 so as to be cooled by an external cooling-medium cooling apparatus (not shown in the figures).
As suitably shown in FIG. 18(b), the first end-face portion 101 of each of the cooling devices 10a and 10b is placed to become parallel with an orthogonal surface which is perpendicular to an inflow direction 11 of the cooling fluid. In addition, the second end-face portion 102 of each of the cooling devices 10a and 10b is placed to become parallel with an orthogonal surface which is perpendicular to an outflow direction 12 of the cooling fluid.
In a conventional rotating electric machine configured as described above, the cooling fluid is transported under pressure by means of the rotating cooling fans 91 and 92, and flowed into the gap 6 from both end portions in axial directions of the stator 4 and the rotor 2. The cooling fluid being transported under pressure into the gap 6 flows through the plurality of stator ducts 8, and outflows into the frame's internal space 7. The cooling fluid outflowed into the frame's internal space 7 flows into each of the cooling devices 10a and 10b through their first end-face portions 101 so as to be cooled by them, and outflows from the second end-face portions 102 of the respective cooling devices 10a and 10b into the frame's internal space 7. The cooling fluid outflowed from the second end-face portion 102 of each of the cooling devices 10a and 10b into the frame's internal space 7 is for a second time transported under pressure by means of the cooling fans 91 and 92, and flowed into the gap 6 from both the end portions of the rotor 2 in axial directions thereof. By the cooling fluid that circulates in the interior of the frame 1 as described above, the rotor 2, the stator 4 and the stator winding(s) 5 are cooled.
FIG. 19(a) and FIG. 19(b) are configuration diagrams illustrating another conventional rotating electric machine which includes cooling fluid ducts mounted on the peripheries of its frame; FIG. 19(a) is the configuration diagram illustrating the machine by a longitudinal section, and FIG. 19(b) is the configuration diagram illustrating it by a cross section. In FIG. 19(a) and FIG. 19(b), on the peripheries of the frame 1 cylindrically formed, the cooling fluid ducts 1a and 1b are mounted, and their internal spaces are allowed to communicate with the interior of the frame 1. Those configurations and other constituent items are equivalent or similar to those conventional devices shown in FIG. 18(a) and FIG. 18(b) described above.
In the interiors of the cooling fluid ducts 1a and 1b, the cooling devices 10a and 10b are mounted, respectively. The placement of each of the cooling devices 10a and 10b in relation to those directions in which the cooling fluid flows is similar to that of the case in FIG. 18(a) and FIG. 18(b) described above. A high-temperature cooling fluid which is flowed, from the interior of the frame 1 corresponding to both end portions in axial directions of the rotor 2 and the stator 4, into each of the cooling fluid ducts 1a and 1b is cooled by each of the cooling devices 10a and 10b to become low temperature, and for a second time, is supplied into the interior of the frame 1 from each of the cooling fluid ducts 1a and 1b, respectively. The low-temperature cooling fluid in the interior of this frame 1 is supplied from the stator ducts (refer to FIG. 18(a)) into the gap similarly to those conventional devices described above referring to FIG. 18(a) and FIG. 18(b), so that the stator and the rotor are cooled. The high-temperature cooling fluid transported, under suction by the cooling fans (refer to FIG. 18(a)), into internal spaces of the frame 1 in both the end portions in axial directions of the rotor and the stator flows for a second time into each of the cooling fluid ducts 1a and 1b as described above, so that the aforementioned circulation is repeated.